Likely just Baader–Meinhof phenomenon[1]. Interestingly, I think that phenomenon ignores the superset of when you actually had seen something multiple times before but for whatever reason started noticing the frequency more frequently (eg you’ve seen backronym’s before, but you’re happening but your brain has decided to notice them more because maybe you saw them in quicker succession than you’re used to).

[1] https://en.wikipedia.org/wiki/Frequency_illusion